The term "Aristotle gap"' is introduced in this work to refer to the angle between the first and last member of a 5-tetrahedral
ring. This gap has angle measure
Aristotle. Book III.8 in On the Heavens (Trans. W. K. C. Guthrie). Cambridge, MA: Harvard University Press, 1939.Doye, J. P. K.
"A Model Metal Potential Exhibiting Polytetrahedral Clusters." 21 Jan 2003.
https://arxiv.org/abs/cond-mat/0301374.Lagarias,
J. C. and Zong, C. "Regular Tetrahedra." Not. Amer. Math. Soc.59,
1540-1549, 2012.